January 26, 2009

No. 07–1122. Argued December 9, 2008—Decided January 26, 2009In Terry v. Ohio, 392 U. S. 1 , this Court held that a “stop and frisk” may be conducted without violating the Fourth Amendment ’s ban on unreasonable searches and seizures if two conditions are met. First, the investigatory stop (temporary detention) must be lawful, a requirement met in an on-the-street encounter when a police officer reasonably suspects that the person apprehended is committing or has committed a crime. Second, to proceed from a stop to a frisk (patdown for weapons), the officer must reasonably suspect that the person stopped is armed and dangerous. For the duration of a traffic stop, the Court recently confirmed, a police officer effectively seizes “everyone in the vehicle,” the driver and all passengers. Brendlin v. California, 551 U. S. 249 .

While patrolling near a Tucson neighborhood associated with the Crips gang, police officers serving on Arizona’s gang task force stopped an automobile for a vehicular infraction warranting a citation. At the time of the stop, the officers had no reason to suspect the car’s occupants of criminal activity. Officer Trevizo attended to respondent Johnson, the back-seat passenger, whose behavior and clothing caused Trevizo to question him. After learning that Johnson was from a town with a Crips gang and had been in prison, Trevizo asked him get out of the car in order to question him further, out of the hearing of the front-seat passenger, about his gang affiliation. Because she suspected that he was armed, she patted him down for safety when he exited the car. During the patdown, she felt the butt of a gun. At that point, Johnson began to struggle, and Trevizo handcuffed him. Johnson was charged with, inter alia, possession of a weapon by a prohibited possessor. The trial court denied his motion to suppress the evidence, concluding that the stop was lawful and that Trevizo had cause to suspect Johnson was armed and dangerous. Johnson was convicted. The Arizona Court of Appeals reversed. While recognizing that Johnson was lawfully seized, the court found that, prior to the frisk, the detention had evolved into a consensual conversation about his gang affiliation. Trevizo, the court therefore concluded, had no right to pat Johnson down even if she had reason to suspect he was armed and dangerous. The Arizona Supreme Court denied review.

(a) Terry established that, in an investigatory stop based on reasonably grounded suspicion of criminal activity, the police must be positioned to act instantly if they have reasonable cause to suspect that the persons temporarily detained are armed and dangerous. 392U. S.,at 24. Because a limited search of outer clothing for weapons serves to protect both the officer and the public, a patdown is constitutional. Id., at 23–24, 27, 30–31. Traffic stops, which “resemble, in duration and atmosphere, the kind of brief detention authorized in Terry,” Berkemer v. McCarty, 468 U. S. 420 , are “especially fraught with danger to police officers,” Michigan v. Long, 463 U. S. 1032 , who may minimize the risk of harm by exercising “ ‘unquestioned command of the situation,’ ” Maryland v. Wilson, 519 U. S. 408 . Three decisions cumulatively portray Terry’s application in a traffic-stop setting. In Pennsylvania v. Mimms, 434 U. S. 106 (per curiam), the Court held that “once a motor vehicle has been lawfully detained for a traffic violation, the police officers may order the driver to get out of the vehicle without violating the Fourth Amendment ,” id., at 111, n. 6, because the government’s “legitimate and weighty” interest in officer safety outweighs the “de minimis” additional intrusion of requiring a driver, already lawfully stopped, to exit the vehicle, id., at 110–111. Citing Terry, the Court further held that a driver, once outside the stopped vehicle, may be patted down for weapons if the officer reasonably concludes that the driver might be armed and dangerous. 434 U. S., at 112. Wilson, 519 U. S., at 413, held that the Mimms rule applies to passengers as well as drivers, based on “the same weighty interest in officer safety.” Brendlin, 551 U. S., at 263, held that a passenger is seized, just as the driver is, “from the moment [a car stopped by the police comes] to a halt on the side of the road.” A passenger’s motivation to use violence during the stop to prevent apprehension for a crime more grave than a traffic violation is just as great as that of the driver. 519 U. S., at 414. And as “the passengers are already stopped by virtue of the stop of the vehicle,” id., at 413–414, “the additional intrusion on the passenger is minimal,” id., at 415. Pp. 5–7.

(b) The Arizona Court of Appeals recognized that, initially, Johnson was lawfully detained incident to the legitimate stop of the vehicle in which he was a passenger, but concluded that once Officer Trevizo began questioning him on a matter unrelated to the traffic stop, patdown authority ceased to exist, absent reasonable suspicion that Johnson had engaged, or was about to engage, in criminal activity. The court portrayed the interrogation as consensual, and, Johnson emphasizes, Trevizo testified that Johnson could have refused to exit the vehicle and to submit to the patdown. But Trevizo also testified that she never advised Johnson he did not have to answer her questions or otherwise cooperate with her. A lawful roadside stop begins when a vehicle is pulled over for investigation of a traffic violation. The temporary seizure of driver and passengers ordinarily continues, and remains reasonable, for the duration of the stop. Normally, the stop ends when the police have no further need to control the scene, and inform the driver and passengers they are free to leave. An officer’s inquiries into matters unrelated to the justification for the traffic stop do not convert the encounter into something other than a lawful seizure, so long as the inquiries do not measurably extend the stop’s duration. See Muehler v. Mena, 544 U. S. 93 . A reasonable passenger would understand that during the time a car is lawfully stopped, he or she is not free to terminate the encounter with the police and move about at will. Nothing occurred in this case that would have conveyed to Johnson that, prior to the frisk, the traffic stop had ended or that he was otherwise free “to depart without police permission.” Brendlin, 551 U. S., at 257. Trevizo was not required by the Fourth Amendment to give Johnson an opportunity to depart without first ensuring that, in so doing, she was not permitting a dangerous person to get behind her. Pp. 7–9.